Alkyl-type phosphoramides

C-F bonds are normally difficult to reduce, but it has now been shown that such bonds a to the carbonyl group of alkyl perfluoroesters can be photoreduced in hexamethylphosphorotriamide in a reaction which involves electron transfer from excited phosphoramide (Portella and Iznaden). Several reports of the photoreduction of carbon dioxide have appeared for photoreduction to methane see Yamase and Sugeta, and Diirr et al. for reduction to formate see Lehn and Ziessel, and Matsuoka et al. Gollnick and Held have reported that mercurochrome is an efficient sensitizer for type II singlet oxygen photo-oxygenations. 

O-o-V"1 gA° R X.H.C R 0 NH2 [52] Amides of different types are produced to form peptido-mimetics and/or peptoids. Not only condensation reactions but also alkylation and substitution reactions are described. Resins/linkers used Wang, Rink amide, Knorr TenlaGel. Phosphoramides were prepared on Pore glass, 3 split-pool libraries. [21] [50-57]... 

Denmark has described several chiral bis-phosphoramides as Lewis base activators of weak Lewis acid SiCL and demonstrated their ability to mediate an enantioselective Passerini-type reaction. Catalytic bis-phosphoramide 36 and stoichiometric SiCU, in the presence of a proton scavenger (Htinig s base), promoted the formation of a-hydroxyamides with remarkably good enantioselectivity and yield. A variety of aromatic and unsaturated aldehydes and aryl, alkyl, and functionalized alkyl isocyanides proved to be useful and effective starting materials. High yields of Passerini products were attributed to the production of imidoyl chloride 37, which reduced the prevalence of the nitrilium intermediate and prevented the addition of a second equivalent of isonitrile. 

---